Abstract: Considering prognosis and life expectancy in patients across all stages of Alzheimer's disease and related dementias improves decision-making. Decisions that are highly influenced by prognosis for older adults with Alzheimer's disease and related dementias include cancer screening, planning financially for nursing home placement, and hospice eligibility. Despite the importance of prognosis, there are no widely-applicable, accurate, and validated tools to estimate prognosis across all stages of Alzheimer's disease and related dementias for patients living in the community. Existing models are either exclusively for persons with advanced dementia in nursing homes, outdated, or suffer from small size or non-generalizable samples. Our goal is to develop a set of clinically useful prognostic models specifically for persons with Alzheimer's disease and related dementias. To maximize the likelihood that these models are accessible to busy clinicians, we will embed these models on eprognosis.org, our online compendium of prognostic calculators. We will develop prognostic models that estimate life expectancy, time to nursing home admission, and risk of death within 6 months for persons with Alzheimer's disease and related dementias in the nationally representative Health and Retirement Study. We will externally validate these models using persons with Alzheimer's disease and related dementias enrolled in the National Health and Aging Trends Study. After validation, these models can be widely used to inform clinical and policy-level decisions for millions of Americans with Alzheimer's disease and related dementias.